A charging system is configured to feed electric power from an electric power system to a secondary battery mounted to an electric moving vehicle to thereby store power in the secondary battery. One of the examples of such charging systems is a wireless charging system in which the electric power system is not connected to the secondary battery in a wired manner. With regard to a technique relating to the wireless charging system, there is known one including a wiring (primary coil) on a transmitting unit side and a wiring (secondary coil) on a receiving unit side which have a structure in which an electric wire is wound in a flattened manner and flat plate-like magnetic cores around which the two wirings are wound (refer to JP-4356844-B). A so-called wired charging system requires a driver of the electric moving vehicle to do some operations including carrying out connection to a plug for electric power feeding installed in a charging station after getting off the vehicle. However, if the wireless charging system is used, the electric power can be supplied from the transmitting unit including the electric power system to the receiving unit having the secondary battery by use of a mutual interaction of electromagnetic induction. As a result, the driver will not have to get on and off the vehicle, and thus his or her convenience will be improved. This kind of technique, however, raises a problem that the wireless connection between the transmitting unit and the receiving unit causes the charging efficiency to be lower.
To increase the charging efficiency in the wireless charging system, it is necessary that a distance between the transmitting unit and the receiving unit during the charging be narrowed to thereby increase the coefficient of magnetic coupling as much as possible. With regard to a technique which was made in the light of this respect, one is known as follows. The transmitting unit (primary side coupler) is stored in a storage room (concave portion) provided on the surface of the earth. A lifting mechanism which is driven by a motor is connected to the transmitting unit. Also, the transmitting unit is ascended by the lifting mechanism to thereby reduce the distance with a receiving unit (secondary side coupler) installed in the electric moving vehicle (refer to JP-2000-152512-A). In addition, there is known another one with which a permanent magnet is disposed on a side of a facing surface of at least one of the transmitting unit or the receiving unit and a gap between the transmitting unit and the receiving unit is narrowed due to the magnetic attractive force of the permanent magnet (refer to JP-2008-120357-A and JP-2008-215028-A).